5,492 research outputs found
On the metrizability of spaces with a sharp base
A base for a space is said to be sharp if, whenever and is a sequence of pairwise distinct elements of
each containing , the collection is a local base at . We answer questions raised by
Alleche et al. and Arhangelski\u{\i} et al. by showing that a pseudocompact
Tychonoff space with a sharp base need not be metrizable and that the product
of a space with a sharp base and need not have a sharp base. We prove
various metrization theorems and provide a characterization along the lines of
Ponomarev's for point countable bases.Comment: 10 pages. Reprinted from Topology and its Applications, in press,
Chris Good, Robin W. Knight and Abdul M. Mohamad, On the metrizability of
spaces with a sharp bas
Low dimensional magnetic solids and single crystal elpasolites: Need for improved crystal growing techniques
The need for extensive crystal growing experiments to develop techniques for preparing crystals suitable for magnetic anisotropy measurements and detailed X-ray and neutron diffraction studies is rationalized on the basis of the unique magnetic properties of the materials and their hydrogen bonded structures which have many features in common with metalloenzyme and metalloprotein active sites. Single crystals of the single and mixed lanthanide species are prepared by the Bridgeman technique of gradient solidification of molten samples. The effects of crystal imperfections on the optical properties of these materials are an important part of the projected research. A series of a-amido acid complexes of first row transition metals were prepared which crystallize as infinite linear chains and exhibit low dimensional magnetic ordering (one or two) at temperature below 40 K
The Clery Act: Student Awareness and Perceptions of Effectiveness at a Public University and a Private College in East Tennessee
The U.S. Congress has recognized that safety is essential on our college and university campuses. Incidents such as the Virginia Tech massacre and the death of Jeanne Clery have emphasized the need for legislation that assists students in selecting a safe college and improves their safety by reducing the incidence of crimes and fires. The Clery Act is a federal law that requires colleges and universities to provide annual information on the number and type of crimes on campus as well as the number and cause of fires occurring in the residence halls. The purpose of this study was to determine the perceived effectiveness of the Clery Act by students at two higher educational institutions in East Tennessee. This study determined that students are not aware of the Clery Act as it relates to the crime and fire statistics to a significant extent. However, students are aware of the Clery Act as it relates to the issuance of safety notices, emergency notifications, or timely warnings by their institution. Students do not tend to use the Clery Act crime and fire statistics in their decisions as to what college to attend, indicating the limited effectiveness of the Clery Act. Lack of use of the Clery Act crime and fire statistics may be related to a lack of awareness of their existence. Students perceive to a significant extent that the reporting of the Clery Act crime and fire statistics as well as the use of safety notices, emergency notifications, or timely warnings, improved their safety and security while on campus. The Clery Act mandated use of safety notices, emergency notifications, or timely warnings issued by the institution results in students changing their behavior to protect themselves and their property. Students perceive that the reporting of crime and fire statistics as well as the use of safety notices, emergency notifications, or timely warnings, has reduced crime and fires on campu
The Clery Act: Student Awareness and Perceptions of Effectiveness at a Public University and a Private College in East Tennessee
The U.S. Congress has recognized that safety is essential on our college and university campuses. Incidents such as the Virginia Tech massacre and the death of Jeanne Clery have emphasized the need for legislation that assists students in selecting a safe college and improves their safety by reducing the incidence of crimes and fires. The Clery Act is a federal law that requires colleges and universities to provide annual information on the number and type of crimes on campus as well as the number and cause of fires occurring in the residence halls. The purpose of this study was to determine the perceived effectiveness of the Clery Act by students at two higher educational institutions in East Tennessee. This study determined that students are not aware of the Clery Act as it relates to the crime and fire statistics to a significant extent. However, students are aware of the Clery Act as it relates to the issuance of safety notices, emergency notifications, or timely warnings by their institution. Students do not tend to use the Clery Act crime and fire statistics in their decisions as to what college to attend, indicating the limited effectiveness of the Clery Act. Lack of use of the Clery Act crime and fire statistics may be related to a lack of awareness of their existence. Students perceive to a significant extent that the reporting of the Clery Act crime and fire statistics as well as the use of safety notices, emergency notifications, or timely warnings, improved their safety and security while on campus. The Clery Act mandated use of safety notices, emergency notifications, or timely warnings issued by the institution results in students changing their behavior to protect themselves and their property. Students perceive that the reporting of crime and fire statistics as well as the use of safety notices, emergency notifications, or timely warnings, has reduced crime and fires on campu
Academic Management — The Case for Challenge
An examination was made of how well certain units involved in managing the teaching-learning organizations of universities work. Criteria for acceptable operation involved clarity of communication, matches between objectives at different levels of the administrative hierarchy, matches between objectives and methods, and rationality of approach to cost-effectiveness. Significant defects were found in relation to each of these criteria suggesting that both selection and training of staff at all levels are now, to some degree, deficient. Inefficiencies relating to poor information gathering, and poor communication were identified as was unnecessary duplication between faculty and department organizations.Nous avons examiné l'efficacité de divers organismes qui gèrent les modalités de l'enseignement et des études au sein des universités. L'opération jugée acceptable devait répondre aux critères suivants: 1) clarté de la communication, 2) corres-pondance des objectifs à divers niveaux de la hiérarchie administrative, 3) corré-lation entre les objectifs et les méthodes, 4) rationalité envers les questions de coût et d'efficacité. Pour chacun de ces critères, nous avons découvert des dis-cordances importantes - ce qui semble indiquer une déficience actuelle dans la sélection et dans la formation du personnel, à tous les niveaux. Ces discordances résultent de la faiblesse des méthodes d'information, du manque de communica-tion, et du fait que, inutilement, les organismes a l'intérieur de la faculté font double emploi avec ceux des départements
Crystal structure of the catalytic fragment of murine poly(ADP-ribose) polymerase-2.
Poly(ADP-ribose) polymerase-1 (PARP-1) has become an important pharmacological target in the treatment of cancer due to its cellular role as a 'DNA-strand break sensor', which leads in part to resistance to some existing chemo- and radiological treatments. Inhibitors have now been developed which prevent PARP-1 from synthesizing poly(ADP-ribose) in response to DNA-breaks and potentiate the cytotoxicity of DNA damaging agents. However, with the recent discoveries of PARP-2, which has a similar DNA-damage dependent catalytic activity, and additional members containing the 'PARP catalytic' signature, the isoform selectivity and resultant pharmacological effects of existing inhibitors are brought into question. We present here the crystal structure of the catalytic fragment of murine PARP-2, at 2.8 A resolution, and compare this to the catalytic fragment of PARP-1, with an emphasis on providing a possible framework for rational drug design in order to develop future isoform-specific inhibitors
Matter effects in the D0-D0bar system
We discuss the impact of matter effects in the D0-D0bar system. We show that
such effects could, in principle, be measured, but that they cannot be used to
probe the mass difference x_D or the lifetime difference y_D. This occurs
because the mixing effects and the matter effects decouple at short times. We
also comment briefly on the B systems.Comment: 6 pages, RevTe
Contemplating Mindfulness at Work: An Integrative Review
Mindfulness research activity is surging within organizational science. Emerging evidence across multiple fields suggests that mindfulness is fundamentally connected to many aspects of workplace functioning, but this knowledge base has not been systematically integrated to date. This review coalesces the burgeoning body of mindfulness scholarship into a framework to guide mainstream management research investigating a broad range of constructs. The framework identifies how mindfulness influences attention, with downstream effects on functional domains of cognition, emotion, behavior, and physiology. Ultimately, these domains impact key workplace outcomes, including performance, relationships, and well-being. Consideration of the evidence on mindfulness at work stimulates important questions and challenges key assumptions within management science, generating an agenda for future research
Ultrasound for Non-invasive Fluid Droplet Detection inside a Sealed Container
Ultrasound has long been known to be capable of measuring water level. Zero-degree ultrasound transducers may be used to send an L-wave through the fluid and receive a reflected signal from the fluid/gas interface surface. The level of the fluid is proportional to the sound wave time of flight to traverse the water path. This approach may even be used from outside the fluid containment wall by sending the wave through the tank or pipe bottom. The approach, however, does not work well if there is only a thin layer of fluid consisting of one or two millimeters or even only a few droplets. Surface waves are also known to be sensitive to the presence or absence of fluid on a surface. A surface wave may be transmitted a significant distance by a transmitting transducer and then received by a similar transducer. If the surface along the wave path is wet with even a few droplets of fluid, the surface wave may be significantly attenuated. Generating and measuring such a surface wave from the opposite side of a tank or pipe containment wall and separating the near-wall surface wave from the far-wall surface wave, however, is more challenging. An approach for producing a surface wave on the opposite side of a steel plate to sense the presence or absence of fluid is discussed. This approach is supported by 2-D finite element modeling of the measurement configuration and by empirical demonstration of the technique’s sensitivity. This technique was developed for measurement of a very small amount of fluid that may condense within a spent nuclear fuel canister after it cools for several years. Such small amounts of fluid are of concern for initiating stress corrosion cracking over the decades that these nuclear waste containment structures are expected to remain leak-free. Early detection of fluid would provide advance warning of potential cracks in time for mitigation or management of the waste inside that container. Other potential applications include any non-intrusive liquid container fluid detection, detection of fluid within inaccessible plena of aircrafts or other complex welded skin structures
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